Eur. Phys. J. E (2006) 20: 401-408
https://doi.org/10.1140/epje/i2006-10029-9

Regular Article

Size and stability of liposomes: A possible role of hydration and osmotic forces

¹ Biophysics and Interfaces Group, Department of Applied Physics, University of Santiago de Compostela, E-15782, Santiago de Compostela, Spain
² Biocolloid and Fluid Physics Group, Department of Applied Physics, Faculty of Sciences, University of Granada, E-18071, Granada, Spain

^* e-mail: fsarmi@usc.es

Received: 19 April 2006
Accepted: 28 July 2006
Published online: 7 September 2006

Abstract

Dynamic light scattering and electrophoretic mobility measurements have been used to characterize the size, size distribution and zeta potentials (ζ-potentials) of egg yolk phosphatidylcholine (EYPC) liposomes in the presence of monovalent ions ( Na⁺ and K⁺). To study the stability of liposomes the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory has been extended by introducing the hydrated radius of the adsorbed ions onto the liposome surfaces. The decrease of liposome size is explained on the basis of the membrane impermeability to some ions which generate osmotic forces, which leads to evacuate water from liposome inside.